With the development of display technology, and people's increasing demand for use of portable information media, in recent years, people have carried on positive studies on a transparent display device, on which an image can be displayed, and which can also make an object behind it visible. At present, transparent display devices are usually used as transparent windows for exhibiting articles.
Currently, a display panel (such as TFT-LCD) can be used as a transparent display device so as to achieve transparent display, and in view of the fact that the display panel does not emit light itself, it is necessary to provide the display panel with a corresponding system light source. For example, it is possible that a LED light bar is used as a system light source, so that light emitted by the LED light bar enters a transparent light guiding plate from its side, the transparent light guiding plate is disposed at the light incident side of the display panel, and light emitted by the system light source is guided by the transparent light guiding plate to enter the display panel for display. Or, for example, it is possible for a lamp box to be used as a system light source for a display panel, that is, articles to be exhibited are placed within the transparent lamp box, the display panel is disposed on one side of the transparent lamp box, and a backlight source is arranged on other side of the lamp box, for transparency display.
Providing a transparent light guiding plate at a light incident side of a display panel will affect the overall transparency of the transparent display device, and then, it will further affect observing exhibited articles that are placed behind the transparent display device; while in the case that a lamp box is used, both the volume and weight of a transparent display device are relatively great, and this goes against lighting and thinning of the transparent display device.